GRAMPS XML is the XML format designed for storing Gramps data. The goal is to have a fully portable, human- and machine-readable XML format so that the data can be read and written without any loss. In addition, XML format allows for smaller files (if compressed) and for using the version control system for tracking the changes (if uncompressed).

The reason XML is not used by Gramps as the working database ("internal") format is performance, specifically memory considerations.